Welcome! Becoming a registered user of ShortWingPipers.Org is free and easy! Click the "Register" link found in the upper right hand corner of this screen. It's easy and you can then join the fun posting and learning about Short Wing Pipers!

Thanks Thanks:  0
Page 1 of 4 123 ... LastLast
Results 1 to 10 of 37

Thread: "Speed" Pacer.

  1. #1

    Join Date
    Oct 2010
    Location
    CEZ3
    Posts
    126
    Post Thanks / Like

    Default "Speed" Pacer.

    So I am leading towards rebuilding my Pacer for cruise speed rather than trying to make it land on a postage stamp. So I am wondering what has been tried on Pacer to improve its cruise speed. Again my experimental Pacer has stock wings and fuselage length. The motor is a Lycoming 0-320 E2D rated for 160hp. Below is a list of items that I would like to do to the plane to make it better:

    -Grove aluminum landing gear with either the streamlined gear legs they offer or aerodynamic gear leg fairings possibly resembling the Pacers original profile.
    -Wing strut fairings. Is there anyone who makes the wing strut to fuselage fairing like the one used on the Mystery Pacer?
    -Miss Pearl fairings "Wing root, flap/aileron hinge"
    -Flap/aileron gap seals
    -Rudder/stabilizer gap seals
    -Negative flap setting "not sure if it will make a difference in cruise speed"
    -Overhead flap handle with electric trim
    -RV-6 cowling and plenum
    -Zero degree engine mount
    -FAB intake system K&N filter
    -Carb inlet closer to prop blast
    -James aircraft RV-10 "6.00 x 6" wheel pants.
    -Tailwheel fairing.
    -Minimize cooling drag through efficient baffling.
    -Exhaust system either 4 pipe or 4-1 along with augmenter. Not sure if cowl flap are required.
    -Rake the windshield more.
    -Windshield to fuselage/wing fairings
    -Strobe lights streamlined into the wings
    -Remove the humpback look.
    -VG's "Stolspeed"
    -Beef up tail structure "Need ideas on this"
    -Wing tips "I'm thinking Stewart gives you the best increase in cruise"
    -Pilot weight loss!

    Already have on the Plane:
    -AeroVolts lithium battery "big weight loss"
    -API 6" tailwheel with stinger "weight loss and less drag"

    Quite a few of my ideas come from Tailwind and BD-4 forums.


    Anyone have any other ideas?

    Thanks!

  2. #2

    Join Date
    Sep 2015
    Posts
    405
    Post Thanks / Like

    Default Re: "Speed" Pacer.

    I would duplicate younkins airplane with a few changes but I think he had a pretty well dialed in

  3. #3
    CamTom12's Avatar
    Join Date
    Jan 2014
    Location
    Huntsville, AL
    Posts
    459
    Post Thanks / Like

    Default Re: "Speed" Pacer.

    Quote Originally Posted by cook11 View Post
    -Grove aluminum landing gear
    -Wing strut fairings. Is there anyone who makes the wing strut to fuselage fairing like the one used on the Mystery Pacer?
    -Miss Pearl fairings "flap/aileron hinge"
    -Flap gap seals
    -Negative flap setting "not sure if it will make a difference in cruise speed"
    -RV-6 cowling and plenum
    -Zero degree engine mount
    -RV-style "6.00 x 6" wheel pants
    -Exhaust system
    -Remove the humpback look
    -VGs
    My Racer has the above listed mods. Others have talked to Roger about the landing gear, it seemed like he thought it was an exceptional amount of work. It sounded like he wouldn't do them again. They are clean though.

    Roger hand-laid fiberglass fairings at nearly every junction on the airplane. I saw his pictures, and other than being tedious for a perfectionist, it didn't seem like it would be that hard to do it yourself.

    I think Roger purchased the flap/aileron hinge fairings. They're pretty tight fitting. I heard a birdie tell me the original design was by Younkin?

    I've also got a reflexed flap setting. Once I get my baffle seals replaced and can do high power runs I'll let you know if they make a big difference at higher speeds. Initial observations show they're probably good for approximately 3-5 mph at 130 mph indicated, but I haven't done any real testing yet.

    I haven't installed the wheel pants yet to see how much of a difference they make. I need to do that and check it out.

    The exhaust is pretty sweet, I'll post who makes it when I get home to check the paperwork. It's a 2-into-1. Sounds real nice. It looks efficient, but Its the only exhaust I've had on the plane so I can't make any comparisons.


    If you have any questions I'll be glad to answer. I didn't build this beautiful plane though, so I might have to phone a friend to get some answers.

  4. #4
    mmoyle's Avatar
    Join Date
    Mar 2013
    Location
    Platinum Alaska
    Posts
    1,745
    Post Thanks / Like

    Default Re: "Speed" Pacer.

    Changing to a zero thrust line will change the cruise angle to nose down and will require the vertical stabilizer to be off set to the left about an inch. I'm going to make wing strut fairings from 3003 fifty thou in two pieces. Fit the halves and weld the seam....then more planishing work to make the weld disappear......but that's way down the road...
    Mark M


    Sent from my iPad using Tapatalk

  5. #5
    Steve Pierce's Avatar
    Join Date
    Nov 2007
    Location
    Graham, Texas, United States
    Posts
    10,070
    Post Thanks / Like
    Blog Entries
    1

    Default Re: "Speed" Pacer.

    Quote Originally Posted by mmoyle View Post
    Changing to a zero thrust line will change the cruise angle to nose down and will require the vertical stabilizer to be off set to the left about an inch. I'm going to make wing strut fairings from 3003 fifty thou in two pieces. Fit the halves and weld the seam....then more planishing work to make the weld disappear......but that's way down the road...
    Mark M


    Sent from my iPad using Tapatalk
    Do you think the thrustline modification will work on a short wing? Because of the difference in the angle of incidence of the wing and my experience Super Cubs with a higher angle of incidence that the modification did not work on I am curious to see.

  6. #6
    piperrocks2013
    Guest

    Default Re: "Speed" Pacer.

    Quote Originally Posted by cook11 View Post
    So I am leading towards rebuilding my Pacer for cruise speed rather than trying to make it land on a postage stamp. So I am wondering what has been tried on Pacer to improve its cruise speed. Again my experimental Pacer has stock wings and fuselage length. The motor is a Lycoming 0-320 E2D rated for 160hp. Below is a list of items that I would like to do to the plane to make it better:

    -Grove aluminum landing gear with either the streamlined gear legs they offer or aerodynamic gear leg fairings possibly resembling the Pacers original profile.
    -Wing strut fairings. Is there anyone who makes the wing strut to fuselage fairing like the one used on the Mystery Pacer?
    -Miss Pearl fairings "Wing root, flap/aileron hinge"
    -Flap/aileron gap seals
    -Rudder/stabilizer gap seals
    -Negative flap setting "not sure if it will make a difference in cruise speed"
    -Overhead flap handle with electric trim
    -RV-6 cowling and plenum
    -Zero degree engine mount
    -FAB intake system K&N filter
    -Carb inlet closer to prop blast
    -James aircraft RV-10 "6.00 x 6" wheel pants.
    -Tailwheel fairing.
    -Minimize cooling drag through efficient baffling.
    -Exhaust system either 4 pipe or 4-1 along with augmenter. Not sure if cowl flap are required.
    -Rake the windshield more.
    -Windshield to fuselage/wing fairings
    -Strobe lights streamlined into the wings
    -Remove the humpback look.
    -VG's "Stolspeed"
    -Beef up tail structure "Need ideas on this"
    -Wing tips "I'm thinking Stewart gives you the best increase in cruise"
    -Pilot weight loss!

    Already have on the Plane:
    -AeroVolts lithium battery "big weight loss"
    -API 6" tailwheel with stinger "weight loss and less drag"

    Quite a few of my ideas come from Tailwind and BD-4 forums.


    Anyone have any other ideas?

    Thanks!


    My AME friend/teacher Ed rebuilt a Piper Pacer many years ago. He never did all what you are going to do. But he was into speed and effiency and other interesting components in many aircrafts more then anything and his work was recognized all over the industry from Bombardier to Cessna across the Us and Canada. Anyhow enough bragging about the great guy He always told me the biggest secret to a speed airplane is the leading edge. Make well sure your leading edge is perfect! No dents should be perfect smooth - think it be hard to hide the rivets, not sure if you can use flush rivet- something to look into. As you know this already make sure you rig the plane perfect and follow the instructions and mostly make it light! Ed's Pacer/ converted Pa22/20 with a 160Hp Full Power Cruise 2500' average temp day was reading close to 150mph and 135 at 2400 RPM. He can't recall but he is sure his prop was the stock 61 or 60.

    Side note story he told me a guy with a Cessna 210 got new paint job and afterwards his cruise wasn't much above 150. (It use to cruise around 180) They tried everything you could think of and no go! Finally Ed looking at the leading edge and notice slight hump and took closer observation and grabbed a pick and started picking on the new paint job. Should of seen the owners face!!! Anyhow to there surprise there was masking tape for some reason left on the leading edge during the paint process. Ed got all the tape off and sanded the leading edge to make it smooth again. Jumped in the 210 and right away got his 180 ++ back. Moral to the story any rough surface no matter what wing we have will affect the performance greatly. Why do you think frost, kills ????? Hope that helps.
    Last edited by piperrocks2013; 12-08-2015 at 07:53 AM.

  7. #7
    CamTom12's Avatar
    Join Date
    Jan 2014
    Location
    Huntsville, AL
    Posts
    459
    Post Thanks / Like

    Default Re: "Speed" Pacer.

    Quote Originally Posted by piperrocks2013 View Post
    Why do you think frost, kills ?????
    Because it creates a rough airfoil surface, which creates a very turbulent boundary layer, which requires more energy to keep the boundary layer attached, which leads to airflow separation.

  8. #8

    Join Date
    Oct 2010
    Location
    CEZ3
    Posts
    126
    Post Thanks / Like

    Default Re: "Speed" Pacer.

    Good points. I feel that by doing that cleanup of the airfoil and any parasitic drag on the wig surfaces will make a noticeable increase in the cruise speed of the Pacer. Combine the major reworking on the cooling drag both on the inlet and exit side, along with a more raked back windshield just like the Tailwind, Hiperbipe and BD-4 will make quite the mover. The raked back windshield will require it to go past the boot cowl and firewall. There are so many junctions on the Pacers airframe that require some nice compound curved fairings that I am certain if done correctly with all the other modifications may get the aircraft really close to the VNE of 170mph no problem. What is limiting the aircraft to a VNE of 170mph? Is it the airfoil? Wing structure? Tail structure?

    CamTom12 did Roger install a zero thrust mount on the Racer for the RV-6 cowling to work?

    Thanks!
    Jon
    Last edited by cook11; 12-08-2015 at 10:52 AM.

  9. #9
    CamTom12's Avatar
    Join Date
    Jan 2014
    Location
    Huntsville, AL
    Posts
    459
    Post Thanks / Like

    Default Re: "Speed" Pacer.

    Quote Originally Posted by cook11 View Post
    CamTom12 did Roger install a zero thrust mount on the Racer for the RV-6 cowling to work?

    Thanks!
    Jon
    I'm not sure, but I'll email him and ask.

  10. #10
    andya's Avatar
    Join Date
    Dec 2007
    Location
    UT47
    Posts
    1,315
    Post Thanks / Like

    Default Re: "Speed" Pacer.

    IMHO - a level flight 170 mph will take a wing other than the clark Y of the piper heritage and no struts for starters
    "Progress is our most important problem"

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •